MobX Quick Start Guide

Creating reference-only observables with @observable.ref

If you are not interested in any changes happening inside a data structure (object, array, map) and only in the change in value, @observable.ref is what you are looking for. It will only monitor reference changes to the observable.

import { observable, action } from 'mobx';class FormData {    @observable.ref validations = null;    @observable username = '';    @observable password = '';    @action    validate() {        const { username, password } = this;        this.validations = applyValidations({ username, password });    }}

In the preceding example, the validations observable is always assigned a new value. Since we are never modifying the properties of this object, it is better to mark it as @observable.ref ...